(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

Make the rrect choices in the following items :

ln fig, , a real image of a point objert O is formed, Which of the following statements is true about each of the arrangements?

(i) The object is at the principle focus of the lens

(ii) The focal length of the lens is 17 cm

(iii) lf the mirror is moved so that it is 6 cm from the lens image will also move

Make the correct choices in the following items : 

A lens used as a magnifying glass

(i) ls a diverging lens

(ii) Produces a virtual image

(iii)  ls placed with the object nearer the lens than the principle focus

Make the correct choices in the following items:

lf the image can be focused on a screen it must be

Make the correct choices in the following items : 

The image formed by a diverging lens, shown in fig, , is

Define the term focus of a lens.

Make the correct choice for each of the following:

Which one of the following Fig correctly shows the path of the ray through the glass block?

Fig. shows two rays of light Op and OQ coming from an object at the bottom of a pond, incident on the water surface.

(a) Mark on the diagram
(i)     The angle of incidence of ray OP,
(ii)    The angle of refraction of ray Op,
(iii)    The position of image of the object as seen from above.
(iv)    An approximate path of the ray OQ.
(b) Explain, why do the rays of light change directions on passing from water to air.
(c) A fish in water sees everything outside the water by rays of light entering its eye in a small cone of light. Draw a diagram and explain how does this happen.

(a)A ray of light is incident at 45° on the face of
(i) A rectangular block of glass.
(ii) A 60⁰ glass prism.
(b) Draw a sketch showing how the ray of monochromatic ray of light passes through glass in each case.
(c) With the aid of a diagram, explain how the face of a right angled prism may totally reflect incident on it.
(d) A thick plane mirror produces several faint images in addition to a prominent one. Draw a ray diagram showing how reflection and refraction produce all these images.
(e) Fig. represents a stone S at the bottom of a pond of water. Using the two rays, as shown, complete the ray diagram to show where the image of the stone appears when viewed from E.

(f) What is a''mirage'? Explain with the help of a diagram.
(g) A man observes the bottom of a swimming pool of 3 m depth. If the refractive index of water is 1.3, what is the apparent depth of water?
(h) When a ray of light undergoes refraction through a glass slab and when it emerges it is displaced laterally (Fig). What are the factors on which the lateral displacement depends?

(i) Fig. shows three rays of light OA, OB and OC passing from water to air, making angles 49⁰, 41⁰ and 35⁰ with the horizontal surface respectively. Draw an approximate path of the emergent ray for each. (Critical angle of water is 49⁰.)

Explain how the principle of echo is used by
The bat during its flight at

Explain how the principle of echo is used by

 The dolphin to locate small fish as its prey